Ontogeny of Larval Pearl-Spotted Killifish Paraphanius mento (Aphaniidae) Distributed in the Nemrut Crater Lake (Eastern Turkiye): A Histological and Microscopic Perspective

Abstract

Abstract: In this study, it was aimed to determine the larval ontogeny of Paraphanius mento (Heckel, 1843), which is distributed in Nemrut Crater Lake (Bitlis, Türkiye). Additionally, embryonic and larval development stages were evaluated microscopically and histologically. Filamentous and sticky fertilized eggs has a diameter of 1.251 ± 0.316 mm with the inclusion of 8−12 oil droplets have started to hatch approximately 11 days after spawning at 23.5°C. It was determined that newly hatched larvae have a total length of around 3.695 ± 0.225 mm (n = 20), have started exogenous feeding at 3 day after hatching and started to take particulate baits at the end of 10 day after hatching. Digestive tract differentiation, hepatopancreas, digestive tubes and gill arches formations were examined by taking histological sections in early life stages.